1. Field of the Invention
The invention relates to millimeter wave transceivers. In particular, the invention relates to a planar millimeter wave transceiver which has right and left hand circular polarization and is formed on a substrate without any crossovers.
2. Description of the Prior Art
Millimeter wave transceivers play an important role in many systems amplifications including radar and electronic countermeasures In the past, millimeter wave transceivers consisted of separate antenna feeds, a monopulse comparator, switches (e.g., switchable latching ferrites), mixers, IF amplifiers and transmitter elements. Most of the items are fabricated in waveguide or combination of waveguide and stripline components. The configurations are complex with many crossovers requiring costly multilayer waveguide interconnection arrangements. In the related application, for example, a compact and simplified antenna feed horn employing a comparator operates in left and right hand circularly polarized modes for establishing azimuth and elevation components. Nonetheless the arrangement is fairly complex and costly.
Monolithic circuits and transceivers have not been extensively used due to the difficulty of locating the circuit elements where they are needed without long line lengths, or crossovers, which add excess insertion loss. A need therefore exists for transceiver circuitry wherein the antenna, transmitter, and receiver can be integrated together in a low cost circuit.